iOS中NSString转换成HEX（十六进制）-NSData转换成int

http://www.2cto.com/kf/201402/281501.html

 

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NSString *str = @ "0xff055008" ; //先以16为参数告诉strtoul字符串参数表示16进制数字，然后使用0x%X转为数字类型 unsigned long red = strtoul([str UTF8String], 0 , 16 ); //strtoul如果传入的字符开头是“0x”,那么第三个参数是0，也是会转为十六进制的,这样写也可以： unsigned long red = strtoul([@ "0x6587" UTF8String], 0 , 0 ); NSLog(@ "转换完的数字为：%lx" ,red);

 

 

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// 十六进制转换为普通字符串的。 + (NSString *)stringFromHexString:(NSString *)hexString { // char *myBuffer = ( char *)malloc(( int )[hexString length] / 2 + 1 ); bzero(myBuffer, [hexString length] / 2 + 1 ); for ( int i = 0 ; i < [hexString length] - 1 ; i += 2 ) { unsigned int anInt; NSString * hexCharStr = [hexString substringWithRange:NSMakeRange(i, 2 )]; NSScanner * scanner = [[[NSScanner alloc] initWithString:hexCharStr] autorelease]; [scanner scanHexInt:&anInt]; myBuffer[i / 2 ] = ( char )anInt; } NSString *unicodeString = [NSString stringWithCString:myBuffer encoding: 4 ]; NSLog(@ "------字符串=======%@" ,unicodeString); return unicodeString; } //普通字符串转换为十六进制的。 + (NSString *)hexStringFromString:(NSString *)string{ NSData *myD = [string dataUsingEncoding:NSUTF8StringEncoding]; Byte *bytes = (Byte *)[myD bytes]; //下面是Byte 转换为16进制。 NSString *hexStr=@ "" ; for ( int i= 0 ;i<[myD length];i++) { NSString *newHexStr = [NSString stringWithFormat:@ "%x" ,bytes[i]& 0xff ]; ///16进制数 if ([newHexStr length]== 1 ) hexStr = [NSString stringWithFormat:@ "%@0%@" ,hexStr,newHexStr]; else hexStr = [NSString stringWithFormat:@ "%@%@" ,hexStr,newHexStr]; } return hexStr; }

 

 

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//int 转data int i = 1 ; NSData *data = [NSData dataWithBytes: &i length: sizeof(i)]; //data 转int int i; [data getBytes: &i length: sizeof(i)];